Well I think this kicked in for me as well today. Flying KL tomorrow 9AM...but no check-in notification whatsoever.
Booking was complete with my email address in the booking, FF number in the booking, and my email address at my FB profile up-to-date. In fact for the outbound flight I did get the notification (tomorrow is inbound).
This sucks because it made me check in a couple hours later than usual, making the good seats being taken by others.